The prior art walker is intended to use commonly for babies who are learning to walk. However, if the walker is sit upon by a grown up baby who has learned already to slide or who is sliding too fast, it would happen a dangerous in speed sliding and that it is therefore vulnerable to an accident.
As shown in FIG. 1, the walker base 10 is generally provided with some rotating wheels 11 and further provided with a fixed guide wheel 12. Between the fixed guide wheel 12 and the walker base 10 of the wheel seat is provided with a brake device 14, which is composed of a ring groove 15, a ball 18, a fixed piece 19, a wheel seat 27, and a shaft rod 30 (as shown in FIG. 2 and 3).
The ring groove 15 is provided at one flank of the fixed guide wheel 12 and further provided with a convex shaft tube 16 at the center. On the circular edge of the ring groove 15 is formed a concave round wave of guide ball trough 17.
The ball 18 is provided inside the guide ball trough 17 of the ring groove 15.
The fixed piece 19 is provided with a center through hole 20 for pivoting with the convex shaft tube 16, so as to enable the fixed piece 19 can be put into the ring groove 15. The bottom edge of the fixed piece 19 is formed a small arc edge 21 to cooperate in coordination with the rolling activity of the ball 18 following the small arc edge 21 to the side edge of the fixed piece 19 having a protruding arc 23 of a retainer 22 at one top end. At the top end center through hole 20 of the fixed piece 19 is provided with a convex piece 24, at the bottom end is provided with a hook 31 of an elastic plate 32 at one end thereof. Around outside of the fixed piece 19 is corresponding to the ring groove 15 extended inside having a seal ring 26 of a flange 25.
The wheel seat 27 is corresponding to the convex shaft tube 16 of the ring groove 15 provided with a pivot hole 28. At the walker base 10 outside of the pivot hole 28 is provided with a back pressure insert piece 33. Corresponding to the fixed piece 19 of the convex piece 24 is provided with a slide way 29.
The shaft rod 30, is fastened pivotally between the convex shaft tube 16 of the fixed guide wheel 12 and the pivot hole 28 of the wheel seat 27, is provided with a spread head 34 at one end thereof. The spread head 34 is fixed automatically with the back pressure insert piece 33 and the hook 31 of the elastic plate 32.
With the brake device 14 as described above, the fixed guide wheel 12 and the ring groove 15 take the advantage of the convex shaft tube 16 to revolve pivoting on the shaft rod 30 of the pivot hole 28 of the wheel seat 27, and fastened pivotally with the fixed piece 19 of the convex shaft tube 16 of the ring groove 15. The convex piece 24 is fixed at the slide way 29. The ball 18, which is provided inside the guide ball trough 17 that has formed concave round wave in the ring groove 15, depends on the revolving of the fixed guide wheel 12 enabling it to roll back and forth under the small arc edge 21 of the fixed piece 19. When the fixed guide wheel 12 is revolved, the guide ball trough 17 guides the ball 18 rising up to the protruding arc 23 of the fixed piece 19, and the ring groove 15 (the fixed guide wheel 12) is braking at once.
The prior art walker as described above is defective in design for the ball 18 is limited between the protruding arc 23 of the fixed piece 19 and the guide ball trough 17 of the ring groove 15, so as to cause the power of brake is not enough while braking. The prior art is further defective in design for the protruding arc 23 is easy to be transfigured by the press pressure of the ball 18, so as to cause the power of brake is not effective in operation. As shown in FIG. 3, the ball 18 from the small arc edge 21 of the fixed piece 19 rises to the protruding arc 23 in procedure to brake taking too much time, so as to cause the revolving of the fixed guide wheel 12 is still rolled fast, and needs to have more time in braking.